Help converting my Victron 24V setup to 48v and some additional questions JBD BMS in series =48v?

brandonboosted

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So I think its time to go from my 24v system to a 48v system, unfortunately this means my multiplus 3000 will be useless and its hardly been used. I had a post a while back with over paneling and heat issues and so forth but I think its just best if I go the 48v route (something I should have done from the beginning). I currently have the Multiplus 3000VA 24v 70A. I noticed the Multiplus-II 48/3000/35-50 120V is much more compact and has a few more capabilities. My main question is what are your thoughts on using this in a residential home? Seems these more target the mobile platform and I want to make sure I am not loosing out on any capabilities/quality that my 24v Multiplus has. My 250/100 will be perfectly suited when on 48v with 4800W. Also I am wondering if anyone has used 2 JBD BMS's in series at 48v and if the internals are rated for that amount.
 

FilterGuy

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I noticed the Multiplus-II 48/3000/35-50 120V is much more compact and has a few more capabilities. My main question is what are your thoughts on using this in a residential home?
In my opinion, Victron equipment is rock solid. They are designed for people that depend on them when out at sea. The primary problem is that they are soooo expensive. You might find something that fits your needs better, but you won't go wrong with Victron. (Note: I am in no way affiliated with Victron, I just like their kit)

Having said that, If you are willing to spend the money on quality with Victron, you should at least look at some of the other quality brands like Schnider and SolArk.

In my mind, the biggest difference between the Multiplus and the Multiplus-II is that the Multiplus is a low-frequency inverter and the Multiplus-II is a high-frequency inverter. This is only an issue when powering loads that have a high turn-on surge (Typically things with motors. More specifically, motors that must startup under a load, like compressors and some power tools.). The rest of the differences are features that may or may not matter to you... it all depends on your overall system design.

Also I am wondering if anyone has used 2 JBD BMS's in series at 48v and if the internals are rated for that amount.
I have not done it, but the JBD BMS has high voltage FETs and can be wired in series. However, if you are going to go to 48V, I would recommend buying a 16S BMS and build out a 48V battery. (If you have to add cells, make them the same brand & size of the existing cells)
I am liking the JK BMS for these types of builds. The only downside of the JK is that you have to have a charge voltage to get them to turn on. (Once they are on, they will stay on till you disconnect them). If you are using Victron charge controllers, this is a minor problem because the Victron charge controllers will generate a charge voltage on the output even if the BMS is turned off.

So I think its time to go from my 24v system to a 48v system,

If you are going to do a massive re-build, it is a great time to re-examine system sizing. Is 3KW enough? More than you need? etc.
 

brandonboosted

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In my opinion, Victron equipment is rock solid. They are designed for people that depend on them when out at sea. The primary problem is that they are soooo expensive. You might find something that fits your needs better, but you won't go wrong with Victron. (Note: I am in no way affiliated with Victron, I just like their kit)

Having said that, If you are willing to spend the money on quality with Victron, you should at least look at some of the other quality brands like Schnider and SolArk.

In my mind, the biggest difference between the Multiplus and the Multiplus-II is that the Multiplus is a low-frequency inverter and the Multiplus-II is a high-frequency inverter. This is only an issue when powering loads that have a high turn-on surge (Typically things with motors. More specifically, motors that must startup under a load, like compressors and some power tools.). The rest of the differences are features that may or may not matter to you... it all depends on your overall system design.


I have not done it, but the JBD BMS has high voltage FETs and can be wired in series. However, if you are going to go to 48V, I would recommend buying a 16S BMS and build out a 48V battery. (If you have to add cells, make them the same brand & size of the existing cells)
I am liking the JK BMS for these types of builds. The only downside of the JK is that you have to have a charge voltage to get them to turn on. (Once they are on, they will stay on till you disconnect them). If you are using Victron charge controllers, this is a minor problem because the Victron charge controllers will generate a charge voltage on the output even if the BMS is turned off.



If you are going to do a massive re-build, it is a great time to re-examine system sizing. Is 3KW enough? More than you need? etc.
Thank you for the response, my 2 reasons I have went with Victron this long are reliability, quality and ease of use (software setup). I will for sure look into those brands though as I don't want to limit my options completely and already invested much more than I intended in this. Have you seen instances of air conditioner/ heat pumps start up cause this issue? Can you refer me to the link because this would definitely be an issue with my setup. I also use power tools and air compressors so this is a concern. Thanks for the FET voltage information, I am planning on just using them in series until my new BMS shows up. I was considering the JK BMS after some reading about it but seems the only thing I am benefiting from would be the active balancer and maybe better software no? 3KW is borderline enough right now but long term would have to be adding another for split phase.
 
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In my mind, the biggest difference between the Multiplus and the Multiplus-II is that the Multiplus is a low-frequency inverter and the Multiplus-II is a high-frequency inverter.
The Multiplus 2 has a transfer switch that handles split phase and bridges the hots in inverter mode.
Its a very attractive feature for the 50 amp RV usage model.
 

FilterGuy

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The Multiplus 2 has a transfer switch that handles split phase and bridges the hots in inverter mode.
Its a very attractive feature for the 50 amp RV usage model.
That is pretty slick. It has some applicability to the stationary/home market as well. You can feed the whole system on 240, but only the 120V appliances will turn on when in battery mode. This might be enough to alleviate the need for a separate critical loads panel.

I do not know enough details on the OPs situation to determine if this is a usable feature or not, but since they mention going to split phase in the future it might be a nice interim step.

As I said, the MP-II has a LOT of features. Whether any particular feature is useful is dependent on the situation.
 

FilterGuy

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I was considering the JK BMS after some reading about it but seems the only thing I am benefiting from would be the active balancer and maybe better software no?
The JK has a broader range of current capability without going to a relay based system..... (I am not a fan of relay-based systems but others swear by them)

3KW is borderline enough right now but long term would have to be adding another for split phase.
I also use power tools and air compressors so this is a concern.
Given what you are describing, I would definitely think twice about another 3K unit that is high frequency.

The general rule of thumb is that High-Frequency inverters can do 2x surge and low frequency can do 3x surge. However, what the rule of thumb does not mention is that the low-frequency inverter can typically sustain the 3x surge for a few seconds and the high frequency inverter can not typically sustain the surge for more than about 1 second.

If 3K is marginally acceptable, then the chance of other things running when a big surge demand happens seems high....and therefor not being able to handle the surge seems high.

Note: Many newer tools and appliances have soft-start and that greatly reduces the surging demand. In addition, some devices can have a soft-start added to them. As part of your planning, you may want to see what can be done on your tools/loads in case you get into an issue with the PM-II
 

Bossrox

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I had 2 victron 150/100's on 24v & they worked flawless for about a year but then I upgraded to 48v. 1 victron fried & a week later the other quit charging & not 'cuz I made any mistakes making the change. I's not rocket science. Victron replaced them but those 2, altho still working, are buggy as hell & need constant intervention to keep 'em up & they won't replace those so I'm thru with them, over priced junk & switched to growatts to see how they do & I might add 3 times cheaper.
 

brandonboosted

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I had 2 victron 150/100's on 24v & they worked flawless for about a year but then I upgraded to 48v. 1 victron fried & a week later the other quit charging & not 'cuz I made any mistakes making the change. I's not rocket science. Victron replaced them but those 2, altho still working, are buggy as hell & need constant intervention to keep 'em up & they won't replace those so I'm thru with them, over priced junk & switched to growatts to see how they do & I might add 3 times cheaper.
How was the warranty process? Did you go through Victron themselves? I hope this is not my fate when I switch my mppt to 48v.
 

brandonboosted

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I understand this is a relatively new inverter from victron but there's little to no reviews and talk about these 48v 120v versions out there.
 

Bossrox

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How was the warranty process? Did you go through Victron themselves? I hope this is not my fate when I switch my mppt to 48v.
Victron will not deal directly with consumers on warranty. They use altEstore as a gatekeeper to verify claims here in the US & a moron named Louis denied my 2nd claim lying about my wiring being improper but was the same as the first 2 that were replaced. I would suggest you change the voltage input in the settings to 48v first before you make the change. I didn't do that not seeing any warnings about such an issue so I'm not even sure if that was the the reason they failed but not standing behind a 2nd claim & the fact the 2nd replacements are malfunctioning in less than a year was enough to show me their brand is no longer reliable in spite of their historical reputation.
 

cinergi

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That is pretty slick. It has some applicability to the stationary/home market as well. You can feed the whole system on 240, but only the 120V appliances will turn on when in battery mode. This might be enough to alleviate the need for a separate critical loads panel.

I do not know enough details on the OPs situation to determine if this is a usable feature or not, but since they mention going to split phase in the future it might be a nice interim step.

As I said, the MP-II has a LOT of features. Whether any particular feature is useful is dependent on the situation.

As long as there are no multi-wire branch circuits in your panel.
 

brandonboosted

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Victron will not deal directly with consumers on warranty. They use altEstore as a gatekeeper to verify claims here in the US & a moron named Louis denied my 2nd claim lying about my wiring being improper but was the same as the first 2 that were replaced. I would suggest you change the voltage input in the settings to 48v first before you make the change. I didn't do that not seeing any warnings about such an issue so I'm not even sure if that was the the reason they failed but not standing behind a 2nd claim & the fact the 2nd replacements are malfunctioning in less than a year was enough to show me their brand is no longer reliable in spite of their historical reputation.
I've never tried changing the settings while just plugged into the usb is that possible? Or are you saying to change it from 24v to 48v right before plugging in the 48v battery?
 

brandonboosted

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Victron will not deal directly with consumers on warranty. They use altEstore as a gatekeeper to verify claims here in the US & a moron named Louis denied my 2nd claim lying about my wiring being improper but was the same as the first 2 that were replaced. I would suggest you change the voltage input in the settings to 48v first before you make the change. I didn't do that not seeing any warnings about such an issue so I'm not even sure if that was the the reason they failed but not standing behind a 2nd claim & the fact the 2nd replacements are malfunctioning in less than a year was enough to show me their brand is no longer reliable in spite of their historical reputation.
My first Victron product was the 250/100, would not recognize pv input at all had to return it as it was DOA. I was hoping this was a fluke as I have heard so much positive things about Victron up until just recently. Also doesn't seem like many people on here run them.
 

Bossrox

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I've never tried changing the settings while just plugged into the usb is that possible? Or are you saying to change it from 24v to 48v right before plugging in the 48v battery?
Yes you can change all parameters from the usb from a windows pc & yes I would change it to 48v before you disconnect it from 24v.
 

CamoGreg

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The Multiplus 2 has a transfer switch that handles split phase and bridges the hots in inverter mode.
Its a very attractive feature for the 50 amp RV usage model.
That is only on the 12/3000 MPII.
The 48/3000 MPII (only other model available in US) requires 2 units for 50A split phase pass through.
 

brandonboosted

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Yes you can change all parameters from the usb from a windows pc & yes I would change it to 48v before you disconnect it from 24v.
The usb doesn't allow access to the device without dc power, how do I switch it to 48v without being on 24v or on 48v with it still on 24v?
 
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